1. Field of the Invention
This invention relates to air powered pressure intensifier cylinders of the type which provides an operating ram pressure applicator initially with a relatively low hydraulic oil operating pressure and, subsequently with a second higher and final operating pressure, the first lower pressure being utilized to advance a ram to which a tool is secured, for instance a punch, to contact a workpiece and the second higher pressure being used to power the ram to perform the actual work on the workpiece, which work may be the piercing of the workpiece by the punch.